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Weight/ Helix/ Gear setup

A

Abindl

Member
Nov 26, 2007
120
13
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38
Denver, Colorado
what is everyone running for a great set up in the 900 long tracks? I'm running 70 weights with a stock helix and 19/ 43 gears on a 92 chain. How am i doing?
 

GKR

Well-known member
Premium Member
Nov 26, 2007
502
177
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Edmonton
Change the helix to a 66/44/.46 and a red/black secondary spring and your golden:)
There are a ton of threads on this on here, do a little search and you'll find lots more info.
 
A

Abindl

Member
Nov 26, 2007
120
13
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38
Denver, Colorado
Its an 05 900. I have a 70-44-46? what do you think? I also only have black/ red spring, not red black.. what is the diffrence in tension?
 
N

Nelson

Well-known member
Nov 30, 2007
1,496
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Libby, Montana/Elko, Nevada
What elevation and riding are you doing?


My 06 900's were set up from 3000'-7500' with complete SLP performance package and my own clutching and gearing which seemed to work really well.

78g SLP MTX weights (74g with 2-2g rivets in each, 78g total)
Green/Pink SLP primary spring (160-340)
Team Lightweight Rapid Reaction Secondary TSS-04
66/44.46 and 66/42.46 Helix with Red/Black spring (140-240)
20/45 gears with custom chain

I think most people are running 11-74 Polaris weights, Green/Pink primary spring, 19/42 gearing, and you more than likely have the TSS-98 Team Secondary that people are also running the 66/44.46 Helix and Red/Black spring in their 05's. Hope this helps out a bit.
 
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GKR

Well-known member
Premium Member
Nov 26, 2007
502
177
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57
Edmonton
You'll like that helix for all round use. It has a very snappy backshift which would serve for you for most all applications, no advantage in drag racing or lake running but everywhere else it's a sweet set-up.
 
G
the 66-44 helix (Part #420719) is the best all around helix for the 900 CFI engine bar none. It does not matter where you run the sled. if you have some HP increasing mods, use the second track with the 70 degree start angle.

you'll need to swap weights and primary springs for elevation changes. But the helix is spot-on for the 900's torque curve on both short and long-tracked sleds.

I am a flatland rider that plays in the deep when we get it, I am on a 2006 900 Switchback bone stock except the 66-44 helix. I also have guys running that same helix on 05-06 900 fusions for lake & trail riding. The clutches stay cool, belts do not explode anymore, and a few MPH gains have been made too.
Polaris really screwed the pooch when the clutched the 900 engines, They must have been looking at the P-85 charts and tried applying that logic to a team unit. It does not work that way at all.
 

mountainhorse

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Dec 12, 2005
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www.laketahoeconcours.com
Change the stock helix

Here is what has been working for me... I've refined it a bit.
Stock 900 with SLP can, no other mods (NO pipe,reeds,head, reflash etc)

All of this info is given assuming that your Belt side clearance on the primary is set to .010" - .020" with the belt you are using AND the deflection is set correctly.

All of the great clutching in the world wont mean squat if these things are not taken care of...

Deflection is easy, side clearance requires specialized tools and holding fixtures and must be done with the clutch removed from the sled.

Secondary

64-42 helix
2 delrin washers in the cup
RED-PINK secondary spring (140-260) [I switched from Red/Black...140-240]

Primary
First and foremost... the primary must be tight, have the faces smooth and be balanced.
11-68 weights
Polaris Almond spring (140-330) or the new spring sytem black-3342 (pn 7043342)

Gearing
19-42 for the 151" and 159"
19-43 for the 166" (requires a 76 pitch chain)


All of this is a bit of science and a lot of trial and error. Find what works for you.

IMO, on the 900's ONLY run the 3211115 belt. It is hands down the most heavy duty belt for these sleds... it only takes one belt blowing under heavy load (when the break most of the time) to snap a crank... The 115 belts usually outlast anything else out there.

===========

Nelson, Aren't you running an SLP pipe/reflash, high compression head, Reeds etc??

That would swing way more weight than a stock 900. and have different backshift character with the tall gearing and the super long track.

Your weights are heavier (78 mtx's = 74 gram 10 series) , but so is the spring.
The back shift will not be as responsive with the heavy weight heavy spring...
Even on the 166 x 2.4" track

I really like the 20-45 gearing (2.25:1) which rests squarely between the 19-42 and 19-43 gearing.... I'll bet that 166 track uses every bit of it!

Yours is still one of my favorite 900's out there!!

MTX™ weights allow you to run 4 grams heavier per weight than you would normally run with OEM weights (ie: if you have been running a 64 gram weight, you should use a 68 gram MTX™ weight).





========================================================
Back-Shifting
Back-shifting occurs when the track encounters an increased
load (demand for more torque). Back-shifting is a function of a
higher shift force within the driven clutch then within the drive
clutch. Several factors, including riding style, snowmobile
application, helix angles, and vehicle gearing determine how
efficient the drive system back-shifts. The desired engine
operating RPM should never fall below 200 RPM when the
drive system back-shifts.

Driven Helix
The helix cam is the primary torque feedback component within
the driven clutch, regardless of driven clutch type. The
beginning angle of the helix must transmit enough torque
feedback to the moveable sheave in order to pinch the drive belt
while minimizing belt slip. The flatter or lower the helix angle,
the more side force will be exerted on the moveable sheave,
while the steeper, or higher the helix angle, the less side force
will be exerted on the moveable sheave.

Helixexplained.jpg
 
M
Feb 5, 2006
7
0
1
Troy, MI
Great thread guys. I have a 06 900 switchback, changed out the track to a 2" shaved down to 1.75", timbersled air intake, and a Dynoport pipe and can. I am embarrased to say I can not remember which gear I changed out, but I did drop down the gearing, in other words to get out of the hole a little better. I put a clutch kit in it, but am not happy with it. I buddy of mine has the same sled but without the mods and put heavy hitter weights in it with good results. Based on me mostly boondocking in the U.P., what set-up for gearing and clutching would you recommend? Thanks in advance.
 
O
Dec 20, 2008
60
6
8
sicamous BC
great thread! I went to the dealer to look into the 115 belt. I asked them about shimming. I'm running the 111 belt and have almost 900 miles on it. everyone says I have to shim it but the 115 belt is about .040 to .060 thinner(JUST LOOKING AT IT) what do I really have to do to go from a 111 belt to a 115? I want to check out my clutching and try to set it up like this thread says. how much is the helix worth to change? please help with belt??
 
N

Nelson

Well-known member
Nov 30, 2007
1,496
73
48
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Libby, Montana/Elko, Nevada
Yes Eric, I have the SLP reflash, High compression domes, reeds etc. Thanks for the comment I like seeing these sleds out there bashing all the haters!:D:D
 
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N

Nelson

Well-known member
Nov 30, 2007
1,496
73
48
39
Libby, Montana/Elko, Nevada
Eric, do you have a part number for the 64-42 Helix? I'm at Lake Tahoe and won't be home until next week and on the phone with my dealer yesterday trying to get one of these Helix's ordered for my buddies 05 900 with 151 to try out when I get back but they say they can't find it. This is for the TSS-98 secondary right? Its not a custom cut Helix is it? Did you mean 62/44.46 maybe?
 
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G
as long as you guys are pulling apart your primary clutches, Check them to see if they need machining to close fully.

many of the 2005 clutches were machined wrong, and the could not fully shift out. Some had weights hitting the spider and binding, others needed material removed from the center so the sheaves could close all the way.


best scenario, send the clutch to "Indy Specialties" in Shakopee MN and have dan go through to make sure they are ok, and get it balanced by him. heck, you may as well send him both clutches, a new 1115 belt, tell him the engine mods you have, elevation you ride, your weight with riding gear, and have him do the whole package for you.

then send him the whole engine in the spring, get his crank and the cases fitted correctly and have a bulletproof bottom end with a 3-year warranty on it!
 
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